Comparative Analysis of the Polyacrylonitrile-Titania and Amidoxime Polyacrylonitrile-Titania Composite Fibers

ABSTRACT This study compares the physical properties such as surface morphology, chemical bonding, crystalline properties, and thermal stability of composite nanofibers produced by reinforcing polyacrylonitrile (PAN) with 5, 8, and 11 wt.% titanium isopropoxide (Tipp) and investigates the strengthening of PAN modified to amidoxime polyacrylonitrile (AOPAN) with 5 wt.% Tipp. The analysis was performed using field emission scanning electron microscopy, atomic force microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and differential scanning calorimetry-thermogravimetric analysis. The results demonstrated the emergence of new bonds, viz., C–N and C=N, when PAN was converted into AOPAN. In contrast, no new bonds were observed when Tipp was added to AOPAN. Consequently, the increase in the average crystalsize and crystallinity was larger (488.235 % and 61.38 %, respectively) when PAN was converted into AOPAN than when the PAN was strengthened with 5 wt.% Tipp (222.8 % and 38.56 %). However, the crystalline properties declined when AOPAN was reinforced with 5 wt.% Tipp. Moreover, after the modification of PAN to AOPAN, the weight loss decreased by 32.53 % owing to a low increase in surface roughness as the root mean square increased by 43.95 % and the fiber diameters increased from 244.315 ± 54.721 nm to 341 ± 69 nm.